Controller

MCU

• Texas Instruments (former Luminary Micro) LM3S5632
• 32-bit 50Mhz ARM Cortex-M3
• 128 KB flash, 32 KB SRAM
• CAN 2.0 controller
• USB 2.0 host/device controller

Ports

• 4 x ADC input (0-3 V measuring range)
• 4 x PWM output (drives up to 600 mA load)
• 2 x CAN connector on 1 bus (10 pin header)
• 1 x SPI
• 1 x I2C
• 1 x UART
• 1 x JTAG (20 pin header)
• 1 x USB device / host (Micro-AB)

Every pin has IO functionality (except PWM) ADC and PWM have 3 pin headers with ground and +5 V

On-board features

• 1 x 350 mW RGB LED
• 1 x Push-button
• ZigBee expansion board (optional)

Electrical

• Supply voltage 5 ± 0,25 V
• Powered from CAN bus, DC jack or USB device port
• Can draw up to 2 A from CAN bus or DC jack and up to 500 mA from USB port after enumeration. This includes on-board electronics.
• Reverse voltage and overcurrent (2 A) protection.

Physical

• Dimensions 61 x 50,6 x 13,2 mm
• Weight ~18 g
• Optional housing (increases height)

ARM-CAN connectors

The following chapters describe each of the connectors on ARM-CAN Controller module. To recognize the connectors the Controller has to be held like shown on the picture.

PWM1 connector

PWM2 connector

PWM1/2 connector has standard RC-servo compatible pinout. In both connectors there are two vertically placed RC-servo pinouts (signal, supply, ground) therefore up to 4 RC-servos can be driven. Controller board supplies up to 2 A total (not counting other consumers) from PWM supply pins. PWM1/2 connector can also be used to drive DC motor which should be connected between leftmost PWM signal pins. Those signals are driven by 5V 600 mA MOSFET half-bridges and can form a full H-bridge. Because of transistors PWM signals can only be used as output.

ADC1 connector

ADC2 connector

Both ADC1 and ADC2 connector have two RC-servo like pinouts. There are ground, supply and input-output pins. It is easy to connect simple sensors like potentiometer, thermistor, IR distance sensor and ultrasonic distance sensor to these pins. IO pins can be used as +5 V compatible inputs or outputs with +3,3 V high level. These connectors can also be used to control RC-servos with software PWM when the servo accepts 3,3 V signal.

COMM connector

COMM connector is a combination of UART, SPI and I2C interfaces. Beside +5 V supply it contains +3,3 V supply which supplies up to 700 mA. COMM connector is intended to connect with ARM-CAN User Interface and that is why it also features 2 ADC and 1 PWM pins, which are used by the joystick and speaker.

JTAG connector

ARM-CAN Controller board has standard 20-pin JTAG connector with essential pins for programming and debugging. Although the kit contains ARM-CAN Programmer other standard ARM debuggers can be used.

CAN connector(s)

ARM-CAN Controller board contains two identical CAN 10-pin header connectors. Both of the connectors are on the same bus, therefore CAN network can be formed by daisy-chaining several Controllers. There is no CAN signal terminator on the Controller board so external terminators should be used.

Microcontroller CAN RX and TX pins which connect to the on-board CAN translator are marked with orange color on the image on side.

USB pins

Controller board incorporates USB micro-AB connector on the right side. Although micro-AB is intended for OTG applications the same connector can be used for device-only and host-only applications. USB inteface has ESD protection on bus and 750 mA fuse on supply line. USB power supply is bi-directional. When Controller acts as a USB device current from USB bus to Controller board flows through Schottky diode, when Controller is used as a host, external power switch to USB bus can be opened with USB_EPEN high signal.

RGB LED pins

In the middle of the Controller board there is a 350 mW RGB LED. Each of the three colors are driven by seperate signal. Green LED has pull-up resistor which lights up green led by default. It can be turned off when microcontroller pin is configured as output with low signal.

BTN pin

There are two buttons on board. The left one resets microcontroller when pressed, the right one is used as a custom button for user application. The button has RC filter which filters button bounces.

• Schematics